Read this interview with sociologist Rodney Stark on how the so-called “mainline” liberal denominations have dwindled into irrelevance: Are Evangelicals the New Mainline? Among the many interesting points he makes is that the only congregations in those traditions that are doing well are those with conservative pastors. And when “evangelicals” decide to go liberal, as in the emergent church or progressive evangelical movement, they decline too. He goes into the history of this phenomenon and finds that it goes way, way back.